Letters: Sprouting spikes

Let me offer a possible explanation for the 'spooky spike'. Both the (frozen) water in the dish and the (liquid or frozen) particles in the air are highly polarisable. So the small particles can be regarded as tiny electrostatic dipoles, and one can imagine that a random distribution of small dipoles near the surface of the freezing polarisable water in the dish can disturb the charge neutrality locally.

A locally excessive charge attracts the airborne dipolar particles in its immediate vicinity, which attach themselves, and a small corrugation in the flat frozen surface appears. Such a protrusion concentrates the excessive charge, thus becoming an even stronger attraction for the particles. The sharper and longer the growing finger, the more it concentrates the electrostatic field close to its tip and the stronger it attracts available particles. This process can lead to the formation of long structures.

Note that it is important ...

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